Kernel Traffic #286 For 30�Nov�2004

I don't think that is a valid argument.

If uClinux wants to be a different source-base, then go wild. But if you want to integrate into the standard kernel, there are other priorities. One of them is that it has to integrate cleanly. And that means that we don't do micro-optimizations that make the non-MMU case affect mainline code unless there is a damn good reason.

No. It's a matter of abstraction. If you can _abstract_ the thing away, that's fine. I don't want more #ifdef's in source code, but you can have a totally different file that doesnt' do the things that aren't appropriate for non-MMU.

Yes, we've already got #ifdef's in code, but the point is that we don't add them unless there is serious _need_. And even then it's a sign of trouble. In this case, the sign of trouble is bigger than the need. uClinux might as well have a dummy "struct vm_operations", if only to make the damn thing look more like real Linux.

I am pleased to announce the availability of a darcs mirror of the linux kernel repository. Darcs is a fully distributed and simple to use revision control system. Instructions on accessing the repository are available at

http://darcs.net/linux.html

In brief, you can get a copy of the latest kernel (converted from the bkcvs branch) using

darcs get --partial http://darcs.net/linux

You can leave out the --partial, if you want to get the full history of the kernel repository (which obviously will take longer).

Be forewarned that darcs is a bit of a memory hog when run with large repositories, so the above command may take quite a while, and probably will require 700 or 800 megabytes of virtual memory. The actual working set of memory is under 300 megabytes. Work is underway to improve both the speed and memory usage of darcs. So far the emphasis in darcs development has been on correctness and stability.

The darcs kernel mirror is sponsored by Aktiom Networks (http://aktiom.net). Aktiom specializes in Linux Virtual Private Servers (VPS) for technology professionals and consultants.

Full history could be preserved, but I don't think that getting it from the web interface would be polite, and I can't run bk myself (for obvious reasons).

I could hack up a sketch of how I'd go about getting the full history. Crudely speaking, I'd just need a couple of functions: one telling me the parents of a given version, and one fetching a given version. And of course, finding the author/date/comments for each version. If someone else were willing to implement those two functions, I could sketch out the darcs side of things. Obviously renames wouldn't be preserved with just those functions, but that's not a huge loss. And also, the conversion process would be painfully slow.

This is the first set of patches to merge some of the new SysKonnect code with existing 2.6 driver and fix several bugs.

1. Remove explicit module refcounting (bug)
2. Make OnesHash table local constant.
3. proc print interface cleanup
4. Use netdev_priv
5. Use module_param_array instead of deprecated MODULE_PARM
6. Add netpoll controller support
7. Basic ethtool support
8. Ethtool support for LED blinking
9. Ethtool pause param support
10. Cleanup
11. Fix boards_found count
12. Add MODULE_VERSION
13. Handle ring full condition properly (bug)
14. Get rid of obfuscation irqreturn_t
15. Rearrange functions to match SysKonnect code
16. More efficient OsGetTime
17. Enable high dma and lockless transmit
18. reorganize pci_device table
19. Do initialization better
20. Ethtool tx & receive checksum efficiently
21. Tx ring management improvements
22. Cleanup the code under DIAG_SUPPORT
23. Eliminate Pnmi scratchpad common

To spare people's mailbox the individual patches won't go to LKML just to netdev.

I talked to Atul and Arjan about this one - the correct thing to do is to replace mdelay() with CPU yielding msleep().

We should backport msleep() in 2.4.29-pre1.

I'm getting the following error:

<-- snip -->

depmod: *** Unresolved symbols in
/lib/modules/2.4.28-rc3/kernel/net/decnet/decnet.o
depmod: neigh_for_each

<-- snip -->

This was caused by Harald's backport of the neighbour scalability fixes from 2.6 .

neigh_for_each must be EXPORT_SYMBOL'ed (as it is in 2.6)

Pacific Digital (and others?) have some PATA and SATA controllers which conform to the public "ADMA" specification found at

http://www.t13.org/project/d1510r1-Host-Adapter.pdf

In terms of standard IDE BMDMA controllers, ADMA is fairly advanced, allowing all commands (including non-DMA) to be transferred using DMA and a scatter-gather table. Rather than a DMA ring, each port has a linked list of commands to execute.

In terms of modern SATA controllers, the ADMA design is showing its age just a tad, but is still a reasonable design. Since the hardware ref is public, and since the driver was quick and easy, I took a couple hours out of the "post-work" evening to write the first draft of the ADMA driver.

This driver conforms to Linus Confidence Level 2:

	It looks right
X	It builds
	It works
	It passes stress tests

The error handling is severely lacking, but this should be basically right.

The driver is built against 2.6.10-rc2 libata.